• The Journal of Korea Robotics Society
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• v.12 no.2
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• pp.107-115
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• 2017

In this paper, four-bar linkage mechanism for the knee joint is developed which is used in prosthetics. But unlike the prosthetics, the feature of this mechanism is that the instantaneous center of rotation of the four-bar linkages can be moved behind the ground reaction force vector so that it can be passively supported without any external power. In addition, this mechanism is developed similar to the structure of the human knee joint for eliminating the sense of heterogeneity of the wearer. In order to design the mechanism with these two objectives, optimization design process is done using the PIAnO tool and detailed design is carried out through optimized variable values. The developed mechanism is attached to the robot which can assist the hip and ankle joints. In order to verify the operation of the developed knee mechanism, an insole type sensor was attached to the shoes to compare data values before and after wearing the robot. Result data showed that wearer wearing the exoskeleton robot with the knee mechanism was the same value regardless of whether the heavy tool is loaded or not.

• Journal of the Korean Society of Industry Convergence
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• v.3 no.2
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• pp.131-139
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• 2000

Gear train in the automobile to be used for controlling gas flow in automobiles consists of spur gears with involute tooth type in multiple stages. This spur gear is designed considering to the high power transfer efficiency, bending stress and contact stress in the static and dynamic analysis. The torque has been increased simultaneously the angular velocity has been decreased through the stages after being supplied by AC synchronous motor. This apparatus is controlled by electrical devices such as the PIC microprocessor, hall sensor and other electric components. By comparing the preset data of PIC microcomputer which is supplied by external DC electric power with the value set of hall sensor which detects the rotation angle position, PIC microcomputer thus controls AC motor and gear train according to the program algorithm which includes the on-off control and PWM motor driving method. As the result of the experiment such as performance, fatigue, torque test, we can conclude that this system is superior to the same and familiar foreign systems.

• Structural Engineering and Mechanics
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• v.56 no.1
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• pp.137-156
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• 2015

In this paper, an analytical solution of displacement, strain and stress field for rotating thick-walled cylinder made of functionally graded material subjected to the uniform external magnetic field and thermal field in plane strain state has been studied. Stress, strain and displacement field as a function of radial coordinates considering magneto-thermo-elasticity are derived analytically. According to the Maxwell electro-dynamic equations, Lorentz force in term of displacement is obtained in cylindrical coordinates. Also, symmetric temperature distribution along the thickness of hollow cylinder is obtained by solving Fourier heat transfer equation in cylindrical coordinates. Using equation of equilibrium and thermo-mechanical constitutive equations associated with Lorentz force, a second-order inhomogeneous differential equation in term of displacement is obtained and will be solved analytically. Except Poisson's ratio, other mechanical properties such as elasticity modulus, density, magnetic permeability coefficient, heat conduction coefficient and thermal expansion coefficient are assumed to vary through the thickness according to a power law. In results analysis, non-homogeneity parameter has been chosen arbitrary and inner and outer surface of cylinder are assumed to be rich metal and rich ceramic, respectively. The effect of rotation, thermal, magnetic field and non-homogeneity parameter of functionally graded material which indicates percentages of cylinder's constituents are studied on displacement, Von Mises equivalent stress and Von Mises equivalent strain fields.

• Women's Health Nursing
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• v.13 no.1
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• pp.43-50
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• 2007

Purpose: There is a need to apply the Tai Chi program to help early mastectomy patients improve their upper limb functions and for the emotional state as well. Method: Participants were recruited at breast cancer centers of two general hospitals from February 17 to April 25, 2005. Twenty-five subjects in the experimental group and 23 subjects in the control group participated for 12 weeks. The Tai chi program consisted of breast cancer self management education and a Tai Chi exercise program. Range of motion of the shoulder joint was determined by the Uni-level inclinometer, and functional assessment of the shoulder was evaluated with the tool. Data was analyzed by SPSS 11. Results: The experimental group had significantly increased shoulder range of motion, especially in external rotation, upper limb function and emotional state compared with the control group after program for 12 weeks. Conclusion: This program makes it possible to be independent and have a positive everyday life. In addition, it can help keep a healthy lifestyle in mastectomy women.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.296-302
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• 2020

The purpose of this study was to assess knee joint loading in the target knee during a golf swing compared to loading rates of high impact activities such as cutting and drop landings. Nine healthy competitive golfers completed golf swings with the target foot both straight and externally rotated 30 degrees, as well as drop landings and cutting maneuvers. Motion capture data was collected at 240 Hz and ground reaction force data was collected at 2400 Hz. The frontal and transverse knee moments were examined using repeated measures ANOVA through SPSS. The abduction moments were higher in golf swings as compared to the other high impact activities (p=.010), while the external rotation moments were lower (p=.003). There were no significant differences between externally rotated and neutral golf swings. These results suggest moments applied to the knee during a golf swing are similar to those applied during a high impact activity.

• Knowledge Management Research
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• v.17 no.4
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• pp.77-104
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• 2016

The effective management of R&D employees is critical for a small or medium sized firm's sustainable growth. R&D employees have professional skills and choose expertise-oriented or management-oriented careers in the process of organizational socialization. This study synthetically verifies the direct and indirect effects of R&D employees' social network and self-esteem on their career orientation by organizational commitment based on social network theory and social recognition theory. The research model has been analyzed through structural equation modeling using survey responses from 220 R&D employees at small- and medium-sized firms in Korea. The analysis results show that internal network activities have direct and indirect impacts on organizational commitment and career orientation, but external network activities do not have significant effects on self-esteem, organizational commitment, or career orientation. There is no consensus in prior studies on whether expert orientation and management orientation are distinct concepts. In this study, these two types of orientation are verified as distinct concepts. It is also found that R&D employees' internal network activities are significant factors for a company's growth. A company should implement an educational system of roles and duties using which individuals can pursue career progression. In addition, it is necessary to provide career development programs such as job rotation, mentoring, and career counseling.

• Physical Therapy Korea
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• v.10 no.1
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• pp.129-137
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• 2003

A single subject experimental design (alternating treatment design) was used to compare the effects of only ultrasound and ultrasound combined with stretching of the joint capsule on the ROM increase and pain reduction in patients with frozen shoulder. Two subjects were included in each group. In the only ultrasound treatment sessions, ultrasound was applied at the pain point of the shoulder joint in supine position. In the ultrasound combined with stretching treatment sessions, ultrasound was applied at the pain point of the shoulder joint positioned in external rotation and abduction in sitting position. Only ultrasound treatment and ultrasound combined with stretching treatment were alternately performed on each patient. Pain and disability was measured by shoulder pain and disability index (SPADI), and range of motion (ROM) was measured by scratch test. The results of this study showed that ultrasound combined with stretching treatment were more effective than only ultrasound treatment in ROM increase and pain reduction. However, disability score was not significantly different.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1113-1120
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• 2016

The purpose of this study is to find the important travel agency service quality factors in relation to the amount of information search efforts through major information channels of customers such as interpersonal source, retailer source, and external media source. Factor analysis using varimax rotation was performed and 20 service attributes of travel agent was reduced to 6 factors; convenience system, personal service, customer maintaining service, reputation, atmosphere and accessibility. According to MANOVA analysis there are significant differences in the service quality factor due to the type of source and amount of efforts of information search.

• Korean Journal of Adult Nursing
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• v.14 no.4
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• pp.554-563
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• 2002

Purpose: to develop an instrument to assess the rehabilitation motivation and to test its reliability and validity. Method: The data was collected with in-depth interviews of nine participants that include adults with disabilities acquired after they reached 18 years' of age. The development of the preliminary items was based on the theory of self-determination proposed by Deci & Ryan (1985) and the results from the analysis of the data. After these, appropriate specialists clarified the validity of the contents of the preliminary items twice. A test to reliability and validity was conducted with 186 disabled. A principal axis factor analysis with oblimin rotation was performed on 29 items. Result: Finally 27 items were selected. The 5-factor solution emerged as the most appropriate model for the data. The different types of motivation for rehabilitation were identified as: task-oriented motivation, change-oriented motivation, obligatory motivation, external motivation, and amotivation. The alpha coefficient of internal consistency was .85. Conclusion: The results of this study suggest that the instrument to measure motivation for the rehabilitation of the disabled may be a useful instrument with a high degree of reliability and validity.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.207-212
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• 2006

Purpose: To evaluate the results of ankle lateral malleolar fractures classified as Danis-Weber type B accompanying osteoporosis that were treated with lag screw. Materials and Methods: 15 cases of Danis-Weber type B ankle lateral malleolar fractures that had T score of less than -2.5 in BMD(bone mineral density) test were selected from June 2003 to December 2005. 10 cases were males and 5 cases were females with mean age of 59 years. The main injury mechanism was supination and external rotation. Mean follow-up period was 16 months. Clinical and radiologic evaluation was done according to Meyer and Kumler's criteria. Results: All cases showed satisfying result and mean radiologic bone union period was 3 months. Anatomic reduction and bone union was acquired in all cases without complications including wound infection, skin necrosis, delayed union and nonunion Conclusions: Lag screw fixation seem to be excellent treatment of Danis-Weber type B lateral malleolar fractures with osteoporosis as it can minimize soft tissue injury and enable anatomic reduction with firm fixation.